• Journal of Embryo Transfer
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• v.32 no.3
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• pp.249-255
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• 2017

In this experiment, we determined the effect of curcumin supplementation in freezing buffer for miniature pig sperm cryopreservation. Each ejaculate was diluted with modified Modena B extender and mixed with lactose-egg yolk (LEY extender, 80% v/v lactose solution [310 mM], 20% v/v egg yolk, and $100{\mu}g/mL$ kanamycin sulfate) and LEY-glycerol Orvus ES Paste (LEYGO, 89.5% v/v LEY, 5% v/v glycerol, 1.5% v/v Orvus ES Paste), 100 mM trehalose supplemented with 0, 10, 50, 100, and $500{\mu}M$ of curcumin from turmeric, respectively. Following equilibration, the 0.5 mL French straws were frozen and plunged into $LN_2$ tank for 7 days at least. Sperm parameter and oxidative byproducts were determined by the computer assisted sperm motility analysis (CASA) and fluorescence-activated cell sorting (FACS) as compared with each groups. Supplementation of curcumin had no effect on sperm motility, progressive motility and curvilinear velocity. However, average-path velocity and straight-line velocity were significantly higher in $10{\mu}M$ curcumin group ($100.9{\pm}8.8{\mu}m/s$, $61.7{\pm}2.9{\mu}m/s$, respectively) than control group ($77.8{\pm}3.9{\mu}m/s$, $46.4{\pm}3.0{\mu}m/s$, respectively) (p < 0.05). In addition, the level of the O2 radical and H2O2 were comparatively decreased in curcumin groups by evaluation of ethidium and DCF fluorescence. According to the results, curcumin can improve sperm kinetic variables and alleviate ROS induced cryoinjury to pig sperm.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.189-198
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• 2009

Tastes and odor in water caused by geosmin and 2-MIB are the major customer complaints for water utilities. Therefore, control of geosmin and 2-MIB is a worldwide concern. In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of geosmin and 2-MIB in BAC filters were investigated. Experiments were conducted at three different water temperatures (5, 15 and $25^{\circ}C$) and four different EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the geosmin and 2-MIB removal in BAC filters. To achieve above 50% of removal efficiency for geosmin and 2-MIB in a BAC filter, above 10 min EBCT at $5^{\circ}C$ and 5 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis for the biodegradation of geosmin and 2-MIB indicated a first-order reaction rate at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for geosmin and 2-MIB. The half-lives evaluated at 5, 15, and $25^{\circ}C$ for geosmin and 2-MIB ranged from 2.39 to 10.31 min and 3.35 to 13.97 min, respectively, which can be used to assist water utilities in designing and operating BAC system.

• Toxicological Research
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• v.12 no.2
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• pp.155-161
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• 1996

The enzymatic properties for NADPH-P450 reductase domain of a fusion protein between human cytochrome P450 1A1 and rat NADPH-P450 reductase expressed in Escherichia coli were investigated. The fusion plasmid pCW/1A1OR-expressed E. coli membrane showed high NADPH-cytochrome c reductase activity ($830.1\pm 85.8 nmol\cdot min^{-1}\cdot mg protein^{-1}$), while pCW control vector and P 450 1A1 expression vector pCW/1A1 showed relatively quite low activity ($4.35\pm 0.49, 3.27\pm 0.50 nmol\cdot min^{-1}\cdot mg protein^{-1}$, respectively). The kinetic curves for NADPH-cytochrome c reductase followed typical Michaelis-Menten kinetics. The $K_{max}$ and $V_{max}$ for NADPH-dependent reductase activity were $8.24\pm 2.61\mu $and $817.9\pm 60.8 nmol\cdot min^{-1}\cdot mg protein^{-1}$, respectively, whereas those for cytochrome c-dependent reductase activity were $19.97\pm 2.86\mu M$ and $1303.5\pm 67.1 nmol\cdot min^{-1}\cdot mg protein^{-1}$. The reductase activities were also compared with those of rat, porcine and human liver microsomes. The activity of pCW/ 1A1OR-expressed E. coli membrane was 15.2-fold higher than that of rat liver microsome. Treatment with benzo(a)pyrene, 7-ethoxyresorufin and $\alpha$-naphthofiavone which are known as specific substrates or inhibitor for human P450 1A1 increased NADPH-cytochrome c reductase activity of fusion protein in E. coli membrane dose-dependently. These results demonstrate that the membrane topology of fused enzyme may be important for activity of its NADPH-P450 reductase domain.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.2
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• pp.83-92
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• 2009

This study was undertaken to examine the effect of oxidants on membrane transport function in renal epithelial cells. Hydrogen peroxide ($H_2O_2$) was used as a model oxidant and the membrane transport function was evaluated by measuring $Na^+$-dependent phosphate ($Na^+$-Pi) uptake in opossum kidney (OK) cells. $H_2O_2$ inhibited $Na^+$-Pi uptake in a dose-dependent manner. The oxidant also caused loss of cell viability in a dose-dependent fashion. However, the extent of inhibition of the uptake was larger than that in cell viability. $H_2O_2$ inhibited $Na^+$-dependent uptake without any effect on $Na^+$-independent uptake. $H_2O_2$-induced inhibition of $Na^+$-Pi uptake was prevented completely by catalase, dimethylthiourea, and deferoxamine, suggesting involvement of hydroxyl radical generated by an iron-dependent mechanism. In contrast, antioxidants Trolox, N,N'-diphenyl-p-phenylenediamine, and butylated hydroxyanisole did not affect the $H_2O_2$ inhibition. Kinetic analysis indicated that $H_2O_2$ decreased Vmax of $Na^+$-Pi uptake with no change in the Km value. Phosphonoformic acid binding assay did not show any difference between control and $H_2O_2$-treated cells. $H_2O_2$ also did not cause degradation of $Na^+$-Pi transporter protein. Reduction in $Na^+$-Pi uptake by $H_2O_2$ was associated with ATP depletion and direct inhibition of $Na^+$-$K^+$-ATPase activity. These results indicate that the effect of $H_2O_2$ on membrane transport function in OK cells is associated with reduction in functional $Na^+$-pump activity. In addition, the inhibitory effect of $H_2O_2$ was not associated with lipid peroxidation.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.115-123
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• 2019

The effects of the Froude numbers on turbulent flow patterns downstream of a non-submerged spur dike were investigated in a laboratory flume. Three-dimensional velocities and water depths were measured using Acoustic Doppler Velocimetry and distance sensors under three Froude number conditions ($Fr_d=0.31$, 0.38, and 0.46). The results show that there are marginal differences in the velocity fields downstream of a spur dike due to the change of the Froude number. However, an increase of the Froude number was found to reduce cross-sectional area in the flow and to increase the strength of the jet-like flow. The jet-like flow was observed to displace the location of the maximum turbulence kinetic energy within a cross section toward the inner bank in the transverse direction.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.459-467
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• 2021

In the majority of countries, the upper limit of buffer temperature in a repository is set to below 100℃ due to the possible illitization. This smectite-to-illite transformation is expected to be detrimental to the swelling functions of the buffer. However, if the upper limit is increased while preventing illitization, the disposal density and cost-effectiveness for the repository will dramatically increase. Thus, understanding the characteristics and creating a database related to the buffer under the elevated temperature conditions is crucial. In this study, a strategy to investigate the bentonite found in Korea under the elevated temperatures from a mineral transformation and radionuclides retardation perspective was proposed. Certain long-term hydrothermal reactions generated the bentonite samples that were utilized for the investigation of their mineral transformation and radionuclide retardation characteristics. The bentonite samples are expected to be studied using in-situ synchrotron-based X-Ray Diffraction (XRD) technique to determine the smectite-to-illite transformation. Simultaneously, the 'high-temperature and high-pressure mineral alteration measurement system' based on the Diamond Anvil Cell (DAC) will control and provide the elevated temperature and pressure conditions during the measurements. The kinetic models, including the Huang and Cuadros model, are expected to predict the time and manner in which the illitization will become detrimental to the performance and safety of the repository. The sorption reactions planned for the bentonite samples to evaluate the effects on retardation will provide the information required to expand the current knowledge of repository optimization.

• Natural Product Sciences
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• v.28 no.3
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• pp.143-152
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• 2022

In our study, sixteen known phenolic compounds, including quercetin (1), methyl gallate (2), caesalpiniaphenol C (3), 8S,8'S,7'R-(-)-lyoniresinol (4), 7,3',5'-trihydroxyflavanone (5), sappanchalcone (6), sappanone A (7), taxifolin (8), fisetin (9), fustin (10), (+)-catechin (11), brazilin (12), 3,4,5-trimethoxyphenyl β-ᴅ-glucopyranoside (13), 1-(2-methylbutyryl)phloroglucinol-glucopyranoside (14), (+)-epi-catechin (15), and astragalin (16) and one mixture of two conformers of protosappanin B (17/18) were isolated from the stems of Caesalpinia decapetala var. japonica. Their structures were elucidated based on a comparison of their physicochemical and spectral data with those of literature. To the best of our knowledge, this represents the first isolation of compounds 3, 4, 8, 9, and 10 from C. decapetala and compounds 13 and 14 from the Caesalpinia genus. All the isolated compounds were evaluated for their inhibitory effect against the α-glucosidase enzyme. Among them, two flavonols (1 and 9), one chalcone (6), and one homoisoflavanone (7) exhibited an inhibitory effect on α-glucosidase action with an IC₅₀ range value of 5.08-15.01 μM, stronger than that of the positive control (acarbose, IC₅₀ = 152.22 μM). Kinetic analysis revealed that compounds 1 and 9 showed non-competitive α-glucosidase inhibition, while the inhibition type was mixed for compounds 6 and 7.

• Journal of Electrochemical Science and Technology
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• v.14 no.1
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• pp.59-65
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• 2023

Sodium hydroxide solutions are often employed as sterilization agents in the pharmaceutical industry. Here, the chloride content is considered as a critical impurity. In this study, an electrochemical method was developed to remove chloride ions (Cl^-) through the oxidative deposition of AgCl on a Ag anode. The Cl^- content in the commercially available 50% w/w NaOH solution employed was approximately 100 mg Cl^-/kg NaOH. As the OH^- content is approximately 18,000 times higher than the Cl^- content, the formation of AgCl may be expected to be thermodynamically less favorable than the formation of Ag₂O. However, activation energies for AgCl and Ag₂O formation have been reported to be approximately 3.8 and 31.2 kJ/mol, respectively, and indicate that AgCl formation is favored. AgCl can be selectively produced by controlling the anode potential. Here, the Cl^- concentration was reduced to less than 50 mg Cl^-/kg NaOH when an anode potential of 0.18 or 0.19 V vs. Hg/HgO (reference electrode) was applied for one hour at 50℃. XRD analysis and visual monitoring of the Ag anode confirmed the oxidative deposition of AgCl on the anode surface as well as the electrochemical desalination of the concentrated NaOH solution.

• Nuclear Engineering and Technology
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• v.19 no.3
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• pp.192-197
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• 1987

Two-point kinetic equations for a compact-core-with-bulky-D$_2$O-reflector system were developed. A unique feature of the system is that certain fission gammas create retarded photoneutrons in the D$_2$O reflector by (ｒ, n) reaction. Coupling effect between the core and the reflector was investigated by simulating power transients with various ramp reactivity insertions. Special attention was paid to the phenomenon associated with spatial separation of photoneutrons and their precursors. Simulations show that accuracy of the two-point model is comparable with that of space-dependent approach. Also it is found that the explicily expressed photoneutron terms in the reflector equation slow down the power transient compared to non-photoneutron expressions. Detectors for reactor power control purpose prefer to be deployed in the core zone to be able to accurately perdict transient power.

• Animal Bioscience
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• v.35 no.10
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• pp.1592-1605
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• 2022

Objective: The objective of this study was to select an effective in vitro digestion-fermentation model to estimate the effect of decreasing dietary crude protein (CP) on odor emission during pig production and to suggest potential prediction markers through in vitro and in vivo experiments. Methods: In the in vitro experiment, three diet formulations with different CP contents (170 g/kg, 150 g/kg, and 130 g/kg) but containing the same standardized ileal digestible essential amino acids (SID-EAA) were assessed. Each diet was evaluated by two different in vitro gastric-intestinal phase digestion methods (flask and dialysis), combined with fresh pig feces-ferment inoculation. Eighteen growing barrows (31.9±1.6 kg) were divided into three groups: control diet (180 g CP/kg, without SID-EAA adjustment), 170 g CP/kg diet, and 150 g CP/kg diet for 4 weeks. Results: The in vitro digestion results indicated that in vitro digestibility was affected by the gastric-intestinal phase digestion method and dietary CP level. According to the gas kinetic and digestibility results, the dialysis method showed greater distinguishability for dietary CP level adjustment. Nitrogen-related odor compounds (NH₃-N, indole, p-cresol, and skatole) were highly correlated with urease and protease activity. The feeding study indicated that both EAA-adjusted diets resulted in a lower odor emission especially in p-cresol and skatole. Both protease and urease activity in feces were also closely related to odor emissions from nitrogen metabolism compounds. Conclusion: Dialysis digestion in the gastric-intestinal phase followed by fresh fecal inoculation fermentation is suitable for in vitro diet evaluation. The enzyme activity in the fermentation and the fecal samples might provide a simple and effective estimation tool for nitrogen-related odor emission prediction in both in vitro and in vivo experiments.